Stovetop brew-in-a-bag???

[MVKTR2]

I'm a long time brewer doing all grain 5 gallon batches with mash tun brewing. However having downsized in space and getting back to brewing I've converted over to 2-gallon fermenters and am thus doing 1.66 gallon batches.

I'm doing brew in a bag for the 2nd time. Making a Scottish /80 and did a thick mash. At the end of 1hr mash I pulled the grain bag, let it drain fairly well, squeezed it just a tad. Then I immediately put the grain bag into a second pot with 1 gal. 170 degree water, gave it a quick thorough stir, pulled the bag out, let it drain, gave it a mild squeeze.

I'm fairly positive the roughly 3 minute grain rinse we'll call it (second pot immersion of grains & stirring) didn't extract any tannins. My question is, am I wrong? I'm a very anal brewer/perfectionist. Btw the reason for doing this was to boil the original sugars down by 2/3 to create some melanoidins & long chain sugars as I always did with the first runnings of my Scottish ales when mash tun brewing.

Thanks,
Phillip

 

[pricelessbrewing]

Since mash out is done at 170, you'll be fine. Actual grain temp probably didn't exceed 165. Don't worry about it.

 

[MVKTR2]

Thanks.

I recall (Been about 20 months since my last brew excluding my first biab 3 weeks ago) from doing modified lauter sparging if you rinse the grains too much you begin to extract tannins. I think the exit gravity isn't supossed to be lower than 1.007 iirc??? as at that point it begins to extract tannins. My guess is with a 3 minute dunk I'm okay. However someone else's experience may be a cautionary tale. I'm here to learn!

 

[whiskeyjack]

Thanks.

I recall (Been about 20 months since my last brew excluding my first biab 3 weeks ago) from doing modified lauter sparging if you rinse the grains too much you begin to extract tannins. I think the exit gravity isn't supossed to be lower than 1.007 iirc??? as at that point it begins to extract tannins. My guess is with a 3 minute dunk I'm okay. However someone else's experience may be a cautionary tale. I'm here to learn!

That has to do with fly sparging I'm pretty sure. After rinsing the grains after a while the wort starts to get pretty thin, below a certain level like you stated can result in negative affects. I'm not an expert on this haha since all I do is BIAB With just a single dunk sparge from BIAB you have no worries of that. You could actually dunk sparge longer then 3 minutes if you wanted

 

[RM-MN]

Extracting tannins requires a high pH, not just a high temperature. Unless your brew water is terribly high pH, your dunk sparge could be done with boiling water if you wanted.

When you fly sparge, you are continuously raising the pH of the grain bed and can extract tannins that way. Measuring the pH of the runoff would be the best way to tell but watching the gravity of the runoff is much easier and as long as you don't go below 1.010 you would be fine.

With a dunk sparge you should never be able to raise the pH enough to extract the tannins unless you do multiple dunks trying to get that last little bit of sugar from the grains.

 

[unionrdr]

I do pb/pm biab for 5 or 6 gallon batches. I mash up to 6lbs+ of grains at 147-156F for an hour. Dunk sparge with 1 1/2 gallons for 10 minutes, stiring once. This gives 3 1/2 gallons boil volume in my 5 gallon kettle.

 

[BlueHouseBrewhaus]

You can do a longer dunk sparge without worrying about tannins. If you want extra insurance, add some acid (I use lactic) to your sparge water to get it below pH of 6. As already said here, you need high pH AND high temp. It doesn't take much acid. I use about .5 ml for 3 - 4 gallons.

 

[MVKTR2]

Thanks for the info and refreshers! BIAB is new to me as is the small batch setup I'm now working with, lots to work out especially when trying to do differing things such as boiling down the first runnings/original mash.

When using my mash tun doing full size batches I averaged 82% mash efficiency. Looks like I got 66% for this biab effort. Tips for improving the efficiency yield? What can I expect in efficiency? Fyi I crush my own grain so that's not a problem.

 

[BlueHouseBrewhaus]

The biggest change is that you can crush very fine since you don't have to worry about stuck sparges. That will really help your efficiency. I started my BIAB brewing "career" at about 65% efficiency. Now I crush very fine, stir the mash every 10-15 min and reserve 8-10 qt for a slow "trickle" sparge thru the raised bag into the BK. Now I get about 80% efficiency.

 

[unionrdr]

The way I described with the crush at /039" gives me higher OG['s across the board. So my efficiency is quite high.

 

[MVKTR2]

The biggest change is that you can crush very fine since you don't have to worry about stuck sparges. That will really help your efficiency. I started my BIAB brewing "career" at about 65% efficiency. Now I crush very fine, stir the mash every 10-15 min and reserve 8-10 qt for a slow "trickle" sparge thru the raised bag into the BK. Now I get about 80% efficiency.

The way I described with the crush at /039" gives me higher OG['s across the board. So my efficiency is quite high.

I use a Corona type mill so my crush is quite severe, more so than what most 'tunners' would accept. Before messing with the crush I'll try a 170 degree dunk sparge for 10 mins. Should that do the trick? Also per someone's comments above I'm possibly not stirring the mash enough during the main mash but can't see how that would make much difference. As is I stirred thoroughly every 20 minutes plus the dough-in.

Which is preferable, rinse sparge with the grains in a colander above the pot or a dunk sparge? A dunk sparge has to be superior correct?

 

[unionrdr]

I've sparged both ways & stirring a ten minute dunk sparge brought my OG's way up. 170F here too. Stir the mash enough to get out all the dough balls so it all gets wetted evenly.

 

[chickypad]

I get 76-79% efficiency basically doing what you described, batch sparge by dunking in a second pot. I don't think you need to let is sit, at least I never do, but I do stir really well for maybe a minute or two. Temp is usually around 150-160 when I remember to heat the sparge water. I don't ever stir the mash once it's well mixed and uniform temp, I just pop it in a preheated oven and leave it alone. I also don't think my crush is that severe, I use the same crush on my larger fly sparge system.

 

[unionrdr]

I like to stir the sparge then let it sit the ten minutes to get plenty of the extra goodies out of them. Add that to the main mash wort to boil volume for the hop additions.

 

[MVKTR2]

Thought I'd update this thread with the fact that an American Stout I brewed Thursday using the improved techniques of double crushing grains and a 10 min mashout in a 2nd pot of 170 degree water yielded much better results.

I hit 81% of efficiency. The negative being my gravity hit 1.075 rather than the planned 1.065 which of course reduces my IBUs in a brew that I was already targeting the lower end of the style for bitterness.

New systems and new processes take time, period! I will say I'm not fond of the amount of trub/grain particulates produced from the brew in the bag approach. However it rather obviously drops out. I'll add the one thing that I don't have a handle on is getting accurate temp readings during the mash. I'm a very experienced brewer and know how to stir a mash till you arm hurts, give it a few minutes to settle then take a reading. Yet no matter what I did with the brew in the bag I had hot-cool spots, like 15+ degrees differences when on the burner. My process is to nail the temp and stuff the pot in the oven for an hour. The problem is nailing the temp ...

Thanks HBTers!

 

[pricelessbrewing]

Don't worry about the ibu, unless you're aiming for a high ibu (iipa or something) you won't notice.

Trub settles out. Temp variation sounds strange, maybe try doughing in a little more gradually? Dough in some, stir like hell, dough in sone more, stir, repeat.